diff -r 612e5ffe9ad3 favorites/src/org/netbeans/modules/favorites/Favorites.java
--- a/favorites/src/org/netbeans/modules/favorites/Favorites.java	Mon Oct 20 18:14:10 2008 +0200
+++ b/favorites/src/org/netbeans/modules/favorites/Favorites.java	Mon Oct 20 18:32:15 2008 +0200
@@ -61,16 +61,18 @@
 import org.openide.filesystems.FileStateInvalidException;
 import org.openide.filesystems.FileUtil;
 import org.openide.filesystems.Repository;
+import org.openide.loaders.ChangeableDataFilter;
+import org.openide.loaders.DataFilter;
 import org.openide.loaders.DataFolder;
 import org.openide.loaders.DataObject;
 import org.openide.loaders.DataShadow;
 import org.openide.nodes.FilterNode;
 import org.openide.nodes.Index;
 import org.openide.nodes.Node;
+import org.openide.util.ChangeSupport;
 import org.openide.util.Exceptions;
 import org.openide.util.ImageUtilities;
 import org.openide.util.NbBundle;
-import org.openide.util.Utilities;
 import org.openide.util.datatransfer.PasteType;
 
 /**
@@ -287,43 +289,71 @@
         }
     }
 
-    private static class Chldrn extends FilterNode.Children 
-    implements ChangeListener, Runnable {
+
+
+    static class VisQ 
+    implements DataFilter.Lowlevel, ChangeableDataFilter, ChangeListener {
+        public static final VisQ DEFAULT = new VisQ();
+
         private ChangeListener weak;
-        private boolean hideHidden;
-        /** Creates new Chldrn. */
-        public Chldrn (Node node, boolean hideHidden) {
-            super (node);
-            this.hideHidden = hideHidden;
-            
+        private ChangeSupport support = new ChangeSupport(this);
+
+        VisQ() {
             weak = org.openide.util.WeakListeners.change(this, VisibilityQuery.getDefault());
             VisibilityQuery.getDefault().addChangeListener(weak);
         }
         
+        public boolean acceptFileObject(FileObject fo) {
+            return VisibilityQuery.getDefault().isVisible(fo);
+        }
+
+        public boolean acceptDataObject(DataObject obj) {
+            return VisibilityQuery.getDefault().isVisible(obj.getPrimaryFile());
+        }
+
+        public void addChangeListener(ChangeListener listener) {
+            support.addChangeListener(listener);
+        }
+
+        public void removeChangeListener(ChangeListener listener) {
+            support.removeChangeListener(listener);
+        }
+
+        public void stateChanged(ChangeEvent e) {
+            support.fireChange();
+        }
+    } // end of VisQ
+    
+    private static class Chldrn extends FilterNode.Children {
+        private boolean hideHidden;
+        /** Creates new Chldrn. */
+        public Chldrn(Node node, boolean hideHidden) {
+            super (node);
+            this.hideHidden = hideHidden;
+        }
+        
         @Override
         protected Node[] createNodes(Node node) {
+            org.openide.nodes.Children ch = Children.LEAF;
+            DataObject obj = node.getLookup().lookup(DataObject.class);
             if (hideHidden) {
-                DataObject obj = node.getCookie(DataObject.class);
                 if (obj != null && !VisibilityQuery.getDefault().isVisible(obj.getPrimaryFile())) {
                     return null;
                 }
             }
+
+            DataFolder folder = node.getLookup().lookup(DataFolder.class);
+            if (folder != null) {
+                ch = new Chldrn(new FilterNode(node, folder.createNodeChildren(new VisQ())), true);
+            } else {
+                if (node.isLeaf()) {
+                    ch = org.openide.nodes.Children.LEAF;
+                } else {
+                    ch = new Chldrn(node, true);
+                }
+            }
             
-            return new Node[] { new ProjectFilterNode (
-                node,
-                (node.isLeaf ()) ? org.openide.nodes.Children.LEAF : new Chldrn (node, true)
-            )};
-        }
-
-        public void stateChanged(ChangeEvent e) {
-            MUTEX.postWriteRequest(this);
-        }
-        
-        public void run() {
-            Node[] arr = original.getChildren().getNodes();
-            for (int i = 0; i < arr.length; i++) {
-                refreshKey(arr[i]);
-            }
+            return new Node[] { new ProjectFilterNode (node, ch) };
         }
     } // end of Chldrn
 
diff -r 612e5ffe9ad3 favorites/test/unit/src/org/netbeans/modules/favorites/VisibilityQueryWorksTest.java
--- a/favorites/test/unit/src/org/netbeans/modules/favorites/VisibilityQueryWorksTest.java	Mon Oct 20 18:14:10 2008 +0200
+++ b/favorites/test/unit/src/org/netbeans/modules/favorites/VisibilityQueryWorksTest.java	Mon Oct 20 18:32:15 2008 +0200
@@ -85,6 +85,7 @@
     /** If execution fails we wrap the exception with 
      * new log message.
      */
+    @Override
     protected void runTest () throws Throwable {
         try {
             super.runTest ();
@@ -96,6 +97,7 @@
     }
 
     
+    @Override
     protected void setUp () throws Exception {
         clearWorkDir();
 
@@ -193,7 +195,10 @@
         VQI vqi = (VQI) Lookup.getDefault().lookup(VQI.class);
         vqi.showAll = true;
         vqi.fire();
-        
+
+        // initialize the children
+        Node some = f.getChildren().findChild(null);
+        assertNotNull("Some node needs to be found", some);
         arr = f.getChildren().getNodes(true);
         assertNodeForDataObject("hidden object is now there", hiddenDO, true, arr);
         assertEquals("One child at all", 1, arr.length);
diff -r 612e5ffe9ad3 openide.loaders/manifest.mf
--- a/openide.loaders/manifest.mf	Mon Oct 20 18:14:10 2008 +0200
+++ b/openide.loaders/manifest.mf	Mon Oct 20 18:32:15 2008 +0200
@@ -1,6 +1,6 @@
 Manifest-Version: 1.0
 OpenIDE-Module: org.openide.loaders
-OpenIDE-Module-Specification-Version: 7.2
+OpenIDE-Module-Specification-Version: 7.3
 OpenIDE-Module-Localizing-Bundle: org/openide/loaders/Bundle.properties
 OpenIDE-Module-Recommends: org.netbeans.modules.templates.v1_0
 AutoUpdate-Essential-Module: true
diff -r 612e5ffe9ad3 openide.loaders/src/org/openide/loaders/DataFilter.java
--- a/openide.loaders/src/org/openide/loaders/DataFilter.java	Mon Oct 20 18:14:10 2008 +0200
+++ b/openide.loaders/src/org/openide/loaders/DataFilter.java	Mon Oct 20 18:32:15 2008 +0200
@@ -41,6 +41,8 @@
 
 package org.openide.loaders;
 
+import org.openide.filesystems.FileObject;
+
 
 /** Allows certain data objects to be excluded from being displayed.
 * @see RepositoryNodeFactory
@@ -61,4 +63,17 @@
     /** @deprecated Only public by accident. */
     @Deprecated
     /* public static final */ long serialVersionUID = 0L;
+
+    /** Additional interface that can be implemented by the {@link DataFilter}
+     * implementors to do low level filtering based on the file objects.
+     */
+    public interface Lowlevel extends DataFilter {
+        /** Should this fileobject be considered for displaying?
+         *
+         * @param fo the file object
+         * @return <CODE>true</CODE> if the object should be displayed,
+         *    <CODE>false</CODE> otherwise
+         */
+        public boolean acceptFileObject(FileObject fo);
+    }
 }
diff -r 612e5ffe9ad3 openide.loaders/src/org/openide/loaders/FolderChildren.java
--- a/openide.loaders/src/org/openide/loaders/FolderChildren.java	Mon Oct 20 18:14:10 2008 +0200
+++ b/openide.loaders/src/org/openide/loaders/FolderChildren.java	Mon Oct 20 18:32:15 2008 +0200
@@ -152,6 +152,12 @@
                     Arrays.sort(arr, order);
                     List<FolderChildrenPair> positioned = new ArrayList<FolderChildrenPair>(arr.length);
                     for (FileObject fo : FileUtil.getOrder(Arrays.asList(arr), false)) {
+                        if (filter instanceof DataFilter.Lowlevel) {
+                            DataFilter.Lowlevel f =(DataFilter.Lowlevel)filter;
+                            if (!f.acceptFileObject(fo)) {
+                                continue;
+                            }
+                        }
                         positioned.add(new FolderChildrenPair(fo));
                     }
 
diff -r 612e5ffe9ad3 openide.loaders/test/unit/src/org/openide/loaders/FolderChildrenTest.java
--- a/openide.loaders/test/unit/src/org/openide/loaders/FolderChildrenTest.java	Mon Oct 20 18:14:10 2008 +0200
+++ b/openide.loaders/test/unit/src/org/openide/loaders/FolderChildrenTest.java	Mon Oct 20 18:32:15 2008 +0200
@@ -47,6 +47,7 @@
 import java.io.IOException;
 import java.util.*;
 import java.lang.ref.WeakReference;
+import java.util.ArrayList;
 import java.util.logging.Level;
 import java.util.logging.Logger;
 import javax.swing.event.ChangeEvent;
@@ -58,12 +59,15 @@
 import org.netbeans.junit.NbTestCase;
 import org.netbeans.junit.NbTestSuite;
 import org.netbeans.junit.RandomlyFails;
+import org.netbeans.spi.queries.VisibilityQueryImplementation;
 import org.openide.filesystems.*;
 
 import org.openide.loaders.DefaultDataObjectTest.JspLoader;
 import org.openide.loaders.MultiDataObject.Entry;
+import org.openide.nodes.AbstractNode;
 import org.openide.nodes.Node;
 import org.openide.nodes.Children;
+import org.openide.nodes.FilterNode;
 import org.openide.nodes.NodeEvent;
 import org.openide.nodes.NodeListener;
 import org.openide.nodes.NodeMemberEvent;
@@ -95,7 +99,7 @@
 
     public static Test suite() {
         Test t = null;
-//        t = new FolderChildrenTest("testDeadlockWithChildrenMutex");
+//        t = new FolderChildrenTest("testALotOfHiddenEntries");
         if (t == null) {
             t = new NbTestSuite(FolderChildrenTest.class);
         }
@@ -732,6 +736,84 @@
         assertNodes( arr, new String[] { "A" } );
     }
 
+    public void testALotOfHiddenEntries() throws Exception {
+        FileSystem fs = Repository.getDefault ().getDefaultFileSystem();
+        FileObject folder = FileUtil.createFolder(fs.getRoot(), "aLotOf");
+        List<FileObject> arr = new ArrayList<FileObject>();
+        final int FILES = 1000;
+        for (int i = 0; i < FILES; i++) {
+            arr.add(FileUtil.createData(folder, "" + i + ".dat"));
+        }
+
+        DataFolder df = DataFolder.findFolder(folder);
+
+        VisQ visq = new VisQ();
+
+        FilterNode fn = new FilterNode(new FilterNode(new AbstractNode(df.createNodeChildren(visq))));
+        class L implements NodeListener {
+            int cnt;
+
+            public void childrenAdded(NodeMemberEvent ev) {
+                cnt++;
+            }
+
+            public void childrenRemoved(NodeMemberEvent ev) {
+                cnt++;
+            }
+
+            public void childrenReordered(NodeReorderEvent ev) {
+                cnt++;
+            }
+
+            public void nodeDestroyed(NodeEvent ev) {
+                cnt++;
+            }
+
+            public void propertyChange(PropertyChangeEvent evt) {
+                cnt++;
+            }
+        }
+        L listener = new L();
+        fn.addNodeListener(listener);
+
+        List<Node> nodes = new ArrayList<Node>();
+        int cnt = fn.getChildren().getNodesCount(true);
+        List<Node> snapshot = fn.getChildren().snapshot();
+        assertEquals("Count as expected", cnt, snapshot.size());
+        for (int i = 0; i < cnt; i++) {
+            nodes.add(snapshot.get(i));
+        }
+        assertEquals("No events delivered", 0, listener.cnt);
+        assertEquals("Size is half cut", FILES / 2, fn.getChildren().getNodesCount(true));
+    }
+
+    public static final class VisQ implements VisibilityQueryImplementation, DataFilter.Lowlevel {
+        public boolean isVisible(FileObject file) {
+            try {
+                int number = Integer.parseInt(file.getName());
+                return number % 2 == 0;
+            } catch (NumberFormatException numberFormatException) {
+                return true;
+            }
+        }
+
+        public void addChangeListener(ChangeListener l) {
+        }
+
+        public void removeChangeListener(ChangeListener l) {
+        }
+
+        public boolean acceptDataObject(DataObject obj) {
+            return isVisible(obj.getPrimaryFile());
+        }
+
+        public boolean acceptFileObject(FileObject obj) {
+            return isVisible(obj);
+        }
+
+    }
+
+
     public static final class Pool extends DataLoaderPool {
         private static Class<? extends DataLoader> loader;